1. Field of the Invention
The present disclosure relates to a lighting device which supplies a current to a solid light emitting element, and a luminaire including the lighting device.
2. Description of the Related Art
Known lighting devices that supply a current to a solid light emitting element such as a light emitting diode (LED) include devices equipped with an AC/DC converter and a DC/DC converter connected to the AC/DC converter. These lighting devices are capable of dimming by controlling an output current of the DC/DC converter. Here, in the case where a dimming level is high (that is, the amount of light is small) in a lighting device, a peak current that flows in switching elements included in the DC/DC converter is reduced. In this case, an invalid current that flows in the circuit of the lighting device is increased, which reduces the efficiency of the lighting device. Some lighting devices made in view of this have been proposed (for example, Japanese Unexamined Patent Application Publication No. 2012-221599). The lighting devices are capable of intermittently driving switching elements in a DC/DC converter when a dimming level is high, and thereby performing deep dimming (achieving a high dimming level) while reducing decrease in a peak current that flows in the switching elements.